1. Field of the Invention
This invention relates generally to building structures with wood roofs, and more particularly to structures exposed to extreme wind conditions, such as Tornadoes and Hurricanes, where building codes dictate that such structures be protected against structural failure to save lives of occupants. In particular, the present invention relates to a roof tie for anchoring a wood frame roof on a block construction building in order to resist uplift forces encountered during a high wind situation.
2. Background of the Prior Art
It is well known what high winds can do to a building, particularly to a wood frame construction low-rise structure. Generally, uplift forces tending to lift the roof off the structure or the entire structure off its foundation cause much of the damage sustained by the building.
Wood structures predominate in residential and light commercial construction, and when wood framing is employed, the structure must be protected from upward loads developed by high wind, which differs with geographical location and is enforced by different building codes for such areas. For example, the Bahamas and Florida, including the Florida Keys are situated in the pathway of the yearly Caribbean hurricane travel course and as such, encounter hurricanes and/or tornadoes from time to time. Houses in the Bahamas are typically constructed of cement block with a wooden top plate fastened to the top of cement block walls, for attaching a wooden roof. In the case of upward loads, the roof is generally tied to the walls using a variety of steel connectors that tie the top plate to the walls. The size and number of these steel connectors vary depending on the severity of the wind conditions in the locality of the building, and the building's geometry. Due to the house location in a susceptible high wind area, some building codes require that houses built with wooden roof support beams have a “Hurricane Tie” in place on every rafter.”
Hurricane Ties” are usually installed during the foundation and framing stages of construction. Laborers hired by the framing contractor generally install connectors and sheathing. Correct size, location, and number of fasteners (nails or bolts) are critical to sustaining the required load. Commonly, such laborers are inexperienced which results in improper or inadequate installation. In all structures, locations of connectors mandate their installation during the framing stage due to related components being placed at the same time. This process slows the foundation and framing stages of construction, which in turn increases labor costs.
From the foregoing, it is apparent that there is a critical need for a strong roof tie system that provides for uplift loads which is cost effective and easy to install.